Abstract
Ethylene glycol dinitrate (EGDN) is a nitrate ester explosive widely used in military ordnance and missile systems. This study investigates the decomposition dynamics of the EGDN cation using a comprehensive approach that combines femtosecond time-resolved mass spectrometry (FTRMS) experiments with ab initio electronic structure and molecular dynamics computations. We identify three distinct dissociation time scales for the metastable EGDN cation of approximately 40-60 fs, 340-450 fs, and >2 ps. The observed dissociation time scales are rationalized by electronic and geometric relaxation of multiple EGDN conformers. These insights are crucial for advancing knowledge of the initial molecular decomposition processes that are central to the detonation physics of nitrate esters, which can lead to improving safety protocols and optimizing the performance of nitrate ester explosives in various applications.